The use of microwaves to thaw viably perserved frozen mammalian organs continues to show promise. This laboratory now has the ability to accurately measure the electrical properties of frozen tissue and precisely thaw solid organs under microcomputer control. This year we propose to complete measurement of dielectric constant and conductivity of perfusates and kidney tissue and explore their spatial distribution for modeling studies. The microcomputer will be utilized to examine resonant frequency shift modulation within the oven for hot spots and thermal runaway. The microcomputer will be utilized to control the thaw for each canine kidney from its signature obtained during its freeze.